Artificial tooth



Dec. 11', 1928.

s. MYERsoN ARTIFICIAL TOOTH Filed March 1925 5imon7igerjon Patented Dec. 11, 1928.

UNITED STATES SIMON MYERSON, OF CAMBRIDGE, MASSACHUSETTS.

ARTIFICIAL TOOTH.

Application filed March 5, 1925. Serial No. 13,108.

This invention relates to an artificial denture including an artificial tooth having a recess in its base and a molded vulcanite or other plate, to which the tooth is attached, by a portion of the plate material entering the recess.

The invention is embodied in the improvements hereinafter described and claimed, in the tooth element of a denture characterized as above stated.

Of the accompanying drawings forming a part of this specification, j 1

Figure 1 is an edge view, on an enlarged scale, of a tooth embodying the invention.

Figure 2 is a rear View, looking toward the lingual face.

Figure 3 is a section on line '3-3 of Figure 2.

Figure'4 is a view similar to Figure 3, showing a portion of a vulcanite plate to which the tooth is fixed.

The same reference characters indicate the same parts in all of the figures.

12 designates the lingual face, and 13 the labial face of a tooth to which my invention relates, these being of any suitable form. The base 14 is preferablyof annular form,

as shown by Figure 2. The tooth is provided with asubstantially conical recess 15, the mouth of which opens upon the base. The wall of the recess tapersfrom the mouth to the bottom, as indicated by Figures 2 and 3.

The recess is adapted to receive a portion 16 of the material from which a'vulcanite plate 16 is formed. The portion 16". is

forced into the recess while the material isplastic, and is formed by the recess wall into an anchoring projection.

The portion 15 of the recess wall nearest the lingual face Y12, and called the lingual side of the recess, is inclined inward from the base toward the lingual face, and is also therefore undercut and interlocked with the The lingual side 15 is end of the tooth, as shown by Figures 3 and 4. The described form of the recess wall is such that it facilitates the displacement of air from the recess by the plate material l6 forced into the same, and prevents liability of the pocketing of air in the recess, and the weakening of retention which would be inspaced from the undercut labial side 15 as shown by Figure 4, so that the projection is retained in contact with the labial side 15 of the recess by the anchoring pin.

The head 20 of the pin is substantially flush with or below the base 14, as shown by Figures 1 and 3, so that it does not project intothe body of the plate 16. The thickness of the portion of the plate body on which the projection 16 is for-med, may, therefore be reduced to a minimum.

I am aware that a crown tooth having a recess in its base, is not new. Heretofore the recess has been of substantially uniform diameter from its mouth to its bottom, or has been slightly larger at the bottom than at the mouth, the form of the recess being such that it is diflicult to completely fill the recess with the plate material, and prevent the pocketing of air at the bottom of the recess.

Teeth as heretofore recessed, are therefore liable to be insuiiiciently retained by the plate material, so that many of such teeth have fallen off. .A porcelain tooth is translucent and the labial side of'the recess heretofore formed has been in such close proximity to the labial face, that the plate material in the recess is dimly visible on the labial face, and has a discoloring effect.

In my. construction, the inclined labial side '15 of the recess provides sufficient thickness betweenit and the labial face to prevent discoloration, and is arranged to ill fering with the packing ofthe plate .mate- 7 rial or Without having a tendency to retain air. 7

I claim: An artificial tooth having a lingual face, 5 a labial face, a base, a recess Whose mouth opens on the base, said recess having a lingual side inclined as a Whole inward from the base toward the lingual face of the tooth and a labial Wall that extends con- 10 tinuously from the inner end of said lin- .the labial face of the tooth, so that said lingual side of the recess is undercut to engage a plate material, and a pin projecting from the labial Wall of the recess and having its outer end Within the recess.

In testimony whereof I have allixed my signature.

SIMON MYERSON. 

